The ones that don't require that stuff are based in Ireland.
Have used http://www.fancyplates.com/ before and they were fine. I like completely "clean" plates all to legal spacing, etc with no additional text (not even the name/postcode of who made them) and they did a great job.
Technically plates have to meet the relevant British Standard (that includes requirements for having the maker of the plate's details and no other text) but I have yet to come across anyone with plates of legal colour / font / size / material / no silly borders that has actually had any trouble with the law.